Gradcolor can be used in a webpage as the body bgcolor but only classic users can see it unless you put your whole page in a table..The code for gradcolor on a webpage would look like this..
<<>html> <<>head> <<>title> <<>/title> <<>/head> <<>body bgcolor="anycolor" text="anycolor" vlink="anycolor" link="anycolor">
<<>table bgcolor="any-color" gradcolor="any-color" width="100%"> <<>tr> <<>td>
here is where you would put the rest of your webpage codes.. you can add gradangle to the code for some interesting affects
<<>/td> <<>/tr> <<>/table> <<>/body> <<>/html>

Gradcolor can not be used for your e-mail background.. you can only use it in a table in you sig body... for gradcolor in your sig body your code should look like this..

The code for the gradcolor table above is..

The table above has gradangle=45 added to the code..

The table above has gradangle=-45 added to the code..

The table above has gradangle=90 added to the code..

The table above has gradangle=-90 added to the code..

The biggest gradangle you can get is 90 degrees or -90 degrees. to get more angle just reverse your bgcolor and gradcolor colors..

The table above has the bgcolor and gradcolor reversed..

The table above has gradangle=45 added to the code..

The table above has gradangle=-45 added to the code..

The table above has gradangle=90 added to the code..

The table above has gradangle=-90 added to the code..

All these codes above are for tables.. which you would use for your sig body after your <<>html><<>body bgcolor="anycolor" text="anycolor">
Then insert your table code for gradcolor..
<<>/body> <<>/html>

you can use any color names, rgb or hex numbers to get the effect you want..